| Named By: | J. C. Merriam in 1906 |
| Time Period: | Middle Triassic - Late Triassic, 250-235 Ma |
| Location: | Germany - Lercheck Limestone Formation, Oberer Hauptmuschelkalk Formation. Norway, Svalbard. USA, Nevada - Prida Formation |
| Size: | Roughly about 2 meters long |
| Diet: | Durophagus carnivore (shellfish eater) |
| Fossil(s): | Several individuals by partial skull and post cranial remains |
| Classification: | | Chordata | Reptilia | Ichthyopterygia | Ichthyosauria | |
Omphalosaurus (from the Greek root "Button Lizard", for their button-like teeth) is an extinct genus of marine reptile from the Middle Triassic, thought to be in the order of Ichthyosauria. Most of what is known about Omphalosaurus is based on multiple jaw fragments, ribs, and vertebrae. Specimens of Omphalosaurus have been described from the western United States, Germany, and the island of Spitsbergen off the northern coast of Norway.